Cage and cartridge assembly for invertible fire extinguisher



Aug. 27, 1957 c. K. HUTHSING, JR

CAGE AND CARTRIDGE ASSEMBLY FOR -INVERTIBLE FIRE EXTINGUISHER FiledSept. 27, 1955 JNVENTOR. CHARLES K. HUTHSINQJR.

Z2412 a TTO NEYS' United States Bi ten-t CAGE AND CARTRIDGE ASSEMBLY FonINVERTIBLE FIRE nxrusoursnun This invention relates generally to animproved structure for a cartridge and tubular cage assembly in aninvertible type fire extinguisher, and more particularly 'to a means ofincreasing the kinetic energy in the cartridge as it moves towards apuncture pin in the extinguisher in response to rotation of theextinguisher from a normal, upright position to an inverted position. I

In a conventional type invertible fire extinguisher, a tubular cage isaxially disposed within the body of the extinguisher and extendsdownwardly from "the collar or tank outlet end. The cage is closed atboth ends and a sealed cartridge is disposed Within the cage for moveentfrom the lower end to the upper end, in response to rotation of theextinguisher from its normal upright position to an inverted position.

In order to break the seal of the cartridge, a puncture pin is securedto the upper end of the cage so that, upon rotation of the extinguisher,the seal of the cartridge will be ruptured by impact with the puncturepin after accelerated movement of the cartridge from the lower end ofthe cage to the upper end of the cage.

The problem with this type of cage and cartridge assembly has been toprovide sufficient kinetic energy in the can tridge, as it moves inresponse to rotation of the extinguisher, to result in the requisiteforce necessary "to break the seal of the cartridge when it comes incontact with the puncture pin. This problem is particularly troublesomewhere'the cartridge must be designed to contain a gaseous fluid (forexample, carbon dioxide) under extremely high pressure with theconsequences that the seal must be correspondingly designed to have highstrength characteristics. In certain applications, therefore, in orderto rupture the seal when it comes in contact with the puncture pin thecartridge must be moving at'a relatively high velocity. V

The problem has been avoided, although not actually solved, in someextinguisher designs by using an external manual means of forcing thepuncture pin through the cartridge instead of depending upon themovement of the cartridge itself to bring about the necessary force. Theuse of an external means, however, requires additional parts as well asan increased expense in the manufacture of the extinguisher, and furtherhas the disadvantage of providing an additional operating step beforethe extinguisher is ready for operation.

It is, therefore, an object of the present invention to provide animproved cartridge and cage assembly for an invertible type fireextinguisher in which suflicient kinetic energy may be imparted to thecartridge as the extinguisher is inverted, whereby a positive'and'efiective puncturing of the cartridge seal will result.

Another object of the present invention is to provide a cartridge andcage assembly according to the previous object in which themodifications necessary to existing invertible extinguisher designs isof such a limited nature that the embodiment of the invention in suchextinguishers will not appreciably affect the overall manufacturingcosts.

A still further object is to provide an improved cage tube and cartridgeassembly for an invertible type fire extinguisher, in which no externalapplication of force is required to break the seal in the cartridge.

These and other objects and advantages of the present invention areattained by providing a cage tube designed to have a flared out portionso as to form an increased diameter section. The cartridge disposed inthe cage for vertical movement is correspondingly modified to include acoupled annular member adapted to be axially disposed within saidincreased diameter section when the extinguisher is in its uprightposition. As the extinguisher is rotated to its inverted position, theannular member is adapted to engage the flared out portion so as torestrain movement of the cartridge towards the upper end of the cagetube assembly until the extinguisher is in a given angular position.

The flared out portion of the cage tube and the annular member coupledto the cartridge are relatively sloped such that the cartridge willslide free of the flared portion when the extinguisher is rotated to thegiven angular position. In practice, an angle of twenty to fortyfivedegrees from the vertical is attained through the engagement of theannular member with the flared out portion of the cage tube before thecartridge is actuated downwardly towards the puncture pin. As aconsequence, it will be evident that the cartridge, when the cage tubeis disposed at twenty to forty-five degrees from the vertical, will berelatively positioned a greater distance from the puncture pin tothereby have an increased potential energy. As a consequence, anappreciably larger kinetic energy will be imparted to the cartridge.

A better understanding of the present invention will be had by referenceto the accompanying drawings, in which preferred embodiments are shownfor illustrative purposes, and in which:

Figure 1 is a partial cross sectional view of the upper portion of atypical, invertible type fire extinguisher with the improved cartridgeand cage tube assembly of the present invention provided therein;

Figure 2 is a View of the cartridge and cage tube assembly in theangular position immediately before the cartridge is about to be freedfor actuation towards the puncture pin;

Figure 3 is a top view of the cartridge;

Figure 4 is an enlarged view of the encircled portion 44 of Figure 3;and

Figure 5 is a partial cross sectional view of the cage tube illustratinga modified form of the present invention.

There is shown in Figure 1 the upper portion of a fire extinguisher 10having a threaded collar 11 on which is mounted a wheel cap 12.

Vertically disposed within the extinguisher 10 is a cage tube 13 havingan annular flange 14 near its upper end and dimensioned so as to besupported on a recessed section 15 on a collar 11. The cage tube 13 isprovided with an upper end closure 16 to which is secured a downwardlyextending puncture pin 17. According to a primary feature of the presentinvention, the cage tube 13 is flared out for its given -diameter toform an increased diameter section in the form of a head 18. The cagetube 13 is further provided with a lower end closure 19, which isadapted to support a cartridge 20 within the tube when the extinguisher10 is in an upright position.

The cartridge 2b, as such, is of a conventional design and is adapted,for example, to contain a compressed gas such as carbon dioxide. Thecartridge has a sealed end 21 to be ruptured when the cartridge 20 comesin contact with the puncture pin 17. As another important part of thepresent invention, the cartridge has coupled near its sealed end 21 anannular member in the form of a pilot ring 22, shown more clearly in theview of- Figure 2. The pilot ring 22 has a plurality of circular cagetube 13 towardsthe puncture pin 17. 7

. 3 apertures 23; the apertures 23 are disposed within the ring 22 todecrease the air resistance the ringoirers to movement of the cartridge21) as it travels through the The cooperative function of the bead 18'and thepilot ring 22 in effecting a more positive rupturing of thesealed end 21 by. the puncture pin 17 will now be described. Theextinguisher 10 is normally vdisposed in the upright position indicatedby Figure 1. When the extinguisher is to be operated, it is turnedupside down to an inverted position, as by rotation in the direction ofthe arrow 24 in Figure 1. As the extinguisher 10 is rotated, thecartridge will fall against the side walls of the cage tube 13, andsimilarly the pilot ring 22 will move radially in one direction tocontact the bead 18.

Through the first ninety degrees of rotation, the cartridge 20 Willalways have a component of force, as a result of its weight, actingtowards the lower end closure 19 and preventing the cartridge fromsliding towards the upper end closure 16. However, after theextinguisher has been rotated ninety degrees, further rotation willresult in a component of force from the weight of the cartridge actingin an axial direction, as designated by the arrow A in Figure 2 towardthe upper end closure 16.

With a conventional cartridge, as soon as the component of force in thedirection of the end 16 overcomes the frictional component of forcebetween the cartridge and the side walls of the cage tube 13, thecartridge will an arcuate portion 26 having a slope adapted to engageand carry the Whole weight of the cartridge 20. When the inclination oftheextinguisher 10 exceeds a given value relative to the slope of thearcuate portion 25, the pilot ring will slip ofii' the portion 25. Inother words, before the cartridge may begin moving towards the puncturepin 17, the extinguisher must be inclined to a position such that at thepoint of engagement between the edge of the pilot ring 22 and theportion 25, there is a component of force from the weight of thecartridge acting axially towards the puncture pin. 1

By delaying movement of the cartridge 20 until the extinguisher has beenrotated 150, for'example, to the angular position of Figure 3, thecartridge 20 is disposed so that it will have a substantially increasedkinetic energy at the time it impacts the puncture pin. This resultsfrom the fact that the cartridge 20 will be held at its initial verticaldistance from the puncture pin 17 until a greater weight component A isprovided, and also from the fact that a smaller component of the weightas represented by the arrow N in Figure 2 of the cartridge will beacting normal to the side walls of the cage tube 13, thereby decreasingthe proportional retarding frictional force with the side walls tendingto prevent acceleration of the cartridge 20 towards the puncture pin.Although the optimum condition would be to have the cartridge 20disposed in a, true vertical position before beginning movement, it hasbeen found in practice that an angle of twenty to forty-fivedegrees withrespect to the vertical imparts suflicient kinetic energy to thecartridge 20 to rupture the sealed end 21 as itimpacts the pin 17. Ofcourse, the necessary angle required will vary to a certain extentaccording to the strength of the sealed end 21, the length of the cagetube 13, and other similar design considerations.

After the cartridge 20 impacts the puncture pin 17 to break the sealedend 21,the pressurized gases within the cartridge will escape andpassout of the cage 13, as through an aperture 26 in the side walls of thecage.

In Figure 5 there is shown a modification to the improvement in the cagetube construction. In this view, instead of providing a bead 18 as inFigure 1, a cage tube 2.7 is shown as having a flared section 28extending outwardly into an increased diameter section of. the cage tube27. The flared out section 28 is equivalent to the use of the head 18since one, arcuate portion 29 of the bead, as seen in Figure 4, does notactually function as a part of the invention, but rather only theportion 25 as discussed previously. The head 18 is used in a preferredconstruction since it is adaptable to embodiment in the cage tube 13 ata lower manufacturing cost.

It will thus be apparent that the improved cartridge and cage tubeassembly of the present invention functions as an automatic means ofproviding the requisite force in an invertible type fire extinguisher toassure a positive puncturing of the seal within the cartridge. Althoughthe drawings show preferred embodiments, it is apparent that changes andmodifications may be made with respect to the flared out section and thecorresponding design of the pilot ring without departing from the spiritand scope of the invention.

What is claimed is:

r 1. In a fire extinguisher operable by rotation from an uprightposition to an inverted position, the combination comprising: a cagetube vertically supported in said extinguisher, said tube having a lowerend closure, and an upper end closure with a puncture pin securedthereto and extending downwardly into said tube, and said tubeadditionally having a flared out portion said flared out portion beinginclined with respect to a plane normal to the axis of said tube andforming an increased diameter section; a cartridge supported within saidtube on said lower end closure, and adapted to move toward said upperend closure in response to rotation of said extinguisher from saidupright position to said inverted position, said cartridge having acoupled annular member spaced from and positioned in opposingrelationship to said flared out portion, said annular member beingdimensioned to frictionally engage said flared out portion and restrainsaid cartridge from movement towards said upper end closure in responseto said rotation until said extinguisher is disposed within at least ofsaid inverted position.

2. The combination according to claim 1, in which said tube is providedwith a bead to define said flared out portion.

3. The. combination according to claim 1, in which said annular memberis providedwith a plurality of apertures.

References Cited in the file of this patent UNITED STATES PATENTS

